1. Field of the Invention
The present invention relates to a touch polarizer and a touch display device; particularly, the present invention relates to a touch polarizer and a touch display device having an integrated design of touch sensing and polarizing structures.
2. Description of the Prior Art
Polarizer is one of the important components of a display device and can allow light having specific polarization direction from a backlight module to pass therethrough, so that the polarizer has a direct influence on brightness and contrast of the display device. For example, a traditional polarizer allows the vertically polarized light to pass therethrough and absorbs the horizontally polarized light; however, this will block at least half of backlight and result in poor light efficiency problem.
An alternative solution is to dispose a dual brightness enhancement film (DBEF) between the traditional polarizer and the backlight module. For example, by utilizing the structural characteristics of the dual brightness enhancement film, the dual brightness enhancement film allows the vertically polarized light to pass therethrough and to arrive the polarizer and reflects the horizontally polarized light. Light reflected by the dual brightness enhancement film will become unpolarized light during transmission, and then a part of the unpolarized light will pass through the dual brightness enhancement film; thus, the backlight can be utilized repeatedly by the dual brightness enhancement film to increase light passing through the polarizer. However, the production cost will be increased when the dual brightness enhancement film is adopted; besides, this solution will add additional thickness to the display device.
Specifically, for a touch display device using either a single polarizer or the polarizer combining with the dual brightness enhancement film, the touch panel and the display device are independent in structure. In other words, in addition to light efficiency problem mentioned above, when the traditional polarizer structure combines with the touch display device, the thickness of the touch display device is still far from ideal, so that the structure of the traditional display device needs to be improved.